Overload relay and circuit breaker



Sept. 16, 1930. c, HORSLEY E AL 1,775,858

ovEnLoAb RELAY AND CIRCUIT BREAKER Filed Feb. 14. 192'! M E a-1 gnuzufoz -3 @ufMM @4% /6 M ywazl;

Patented Sept. 16, 1930 UNITED STATES PATENT OFFICE CAPERTON HORSLEY AND EDWIN R. GOLDFIELD, OF CLEVELAND, OHIO, ASSIGNORS TO THE ENGELN ELECTRIC COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO OVERLOAD RELAY AND CIRCUIT BREAKER Application filed February 14, 1927. Serial No. 168,052.

This invention relates to electrical controlling means and the principal object of the invention is to provide a means of complete remote control with the accompanying advantages of convenience, the apparatus controlled being provided with protective units such as overload relays, ordinarily requiring resetting by hand manipulation.

Our invention embraces more specifically, means also for resetting the overload relay usually provided, and without the expense or space required by a separate coil for this purpose.

Our invention also comprises an arrangemerit of wiring and control switches so that when the relay is being reset it is impossible for current to be delivered to the load.

Another object of the invention is to provide a means of varying the sensitivity of the relay by the use of a selector switch whereby the control means may be preset to automatically open the load circuit at a selected one of a number of load limits.

The exact nature of the invention and further objects and advantages thereof will be obvious from the following description taken in connection with the accompanying drawings inwhich Fig. 1 is a diagrammatic representation of the apparatus, the parts thereof being generally in normal relative positions but with load off Fig. 2 is a detail of the relay switch and toggle mechanism in instantaneous intermediate position; and Fig. 3 is a similar view showing the toggle mechanism in broken position.

In the drawings 1 represents the load element of the apparatus, arranged for energiz ation from a source of a current supply L 11 ,2 representing generally a magnetic circuit breaker and 6 generally an overload relay.

The load is in direct connection with L and immediately controlled by movement of the switch arm 4 of the circuit breaker, making or breaking contact with the fixed contactor 5 to close or open the load circuit. In the load circuit is also arranged coil 6 of an overload relay; a connection being provided between the breaker switch 4 and one end of the relay coil, the coil being provided with taps as indicated, leading to points b, 0, of a selector switch 7 the other element of the switch being in connection with L An electromagnet 8 is arranged in the usual manner for energization to close the circuit breaker, and according to our invention is manually controlled subject to conditions to be described, by the hand load controlling switch 9; a relay switch 10 being also provided in this circuit for a purpose to be described. An additional parallel circuit may be established for the magnet 8, independent of switches 9 and 10, by an auxiliary point 7 on the resetting and selectorswitch 7; a spring 18 being arranged on the switch 7 so that the movable switch arm thereof will not remain upon the point 7 to maintain this circuit closed, and while on the point 7 is incapable of simultaneously contacting with either of the oints 7 b or 7 The member 10 of the switch 10 is of spring material and of tendency to open away from its cooperative switch member but normally maintained closed by an arrangement to be described and which forms an interconnection between the overload relay and the magnetic circuit breaker.

This arrangement comprises a double toggle mechanism generally designated by the numeral 3 consisting of linkage members cl, 6, and The toggle members are supported upon a bracket 11, the member 3 being in pivotal connection with the bracket at 1:2, the member 3 carrying a roller 13 of nonconductive material adapted to contact with the member 10 of the switch 10 to close the same, and guided in the slots indicated upon the bracket for rotational and bodily movement; the members 3 and 8 are interconnected by the link member 6.

The coil 6 surrounds a tubular member 14 which forms a guide for a magnetically responsive armature 15 normally resting upon the bottom of member 14, the arrangement being such that the armature will be caused to fly upwards upon sufficient energization of the coil 6.

The upper end of the member 14 is open and extends through the bracket 11, and the arrangement and proportion of the toggle mechanism is such that the joint between the members 3 and 3 thereof is in the line of motion of armature 15. The member 3 is in fact a lever, the free arm of which carries a roller 16 of nonconductive material adapted to be engaged by the breaker switch a to reset the toggle mechanism in the position indicated in Fig. 1, and of weight sufficient to tend to maintain the toggle mechanism in the position indicated in Fig. 3.

Assuming the parts in the position indicated in Fig. 1,the operation of the control means is as follows: Movement of the arm of switch 7 to make contact at 7 effects energization of the coil 8 to close the breaker switch and to move the lever 3 of the toggle mechanism to set this mechanism in the position indicated in Fig. 1 if not already so set. The toggle mechanism is arranged to main tain this position; the bracket 11 which limits downward movement of the joints between the members 8 8 and 3 allowing he two in termediate free joints in straightened posi tion of the toggle, to actually lie slightly below a line between the center of the roller 13 and the pivot point 12; the action of the spring switch member 10 against the roller 13 being sutlicient to overcome the tendency of the weight of the roller 16 to break the toggle.

The switch 7 is next set to contact at T or 7 thus preselecting the number of turns of the coil 6 in circuit with the breaker switch 4 and predetermining the relative strength of coil 6 and therefore the amount of load which will be required to effect movement of the armature 15;, or in other words presetting a maximum load limit.

Closing of the switch 9 completes a circuit for the breaker coil 2, which circuit includes, between L and L the switch 10.

The control means thereafter remains as described until manual opening of the switch 9, or until. such maximum predetermined load is attained, whereupon the coil 6 causes the armature 15 to fly upwards, breaking upwards the joint between the members 3 and of the toggle 3 and allowing the spring switch member to open the circuit through the switch 10. 'Opening of the switch 10, which is in circuit with the magnet coil of the circuit breaker 2, allows the breaker switch 4 to drop to the position of Fig. 1 opening the load circuit.

Immediately following the breaking of the joint between the members 8 and 3 however, and consequent relief of compression in the toggle, the jointed end of the unbalanced lever 3 is immediately elevated and the oint between the members 3 and 3 returns to rest upon the bracket 11, the parts then being in the position of Fig. 3. The switch 10 being now opened and the magnet 8 deenergized the breaker switch remains open. The armature of course has meanwhile returned to the position indicated.

Thereafter movement of the switch 7 to contact at 7 is required as before to again close the breaker switch and simultaneously preset the toggle mechanism by engagement of the member 4 with the roller 16 of the member 8 What we claim is:

1. Control means for electric apparatus comprising a load circuit, a magnetic circuit breaker having a switch in said load circuit and an actuating coil, an overload relay having a switch and electromagnetic means arranged in said load circuit and means associating said electromagnetic means with said relay switch to open the latter upon predetermined energization of the. former, connecting means arranged for actuation by closing movement of said breaker switch to close said relay switch, operator-controlled means for energization of said breaker coilrto close said relay switch, and operator-controlled means for energizing said breaker coil dependent upon closing of, said relay switch, whereby said apparatus may be operated subject to being disconnected by the opening of said breaker in response to said overload relay.

2. Control means for electric apparatus comprising a load circuit, a magnetic circuitbreaker having a switch in said load circuit and an actuating coil, an overload relay having a switch and electromagnetic means and means associating said electromagnetic means with said relay switch to open the latter upon predetermined energization of the former, means for including selected portions of said electromagnetic means in said load circuit, connecting means arranged for actuation by closing movement of said breaker switch to close said relay switch, operator-controlled means for energization of said breaker coil to close said relay switch, and operator-controlled means for energizing said breaker coil dependent upon closing of said relay switch, whereby said apparatus may be operated subject to being disconnected by the opening of said breaker in response to said relay.

3. Control means for electric apparatus comprising a load circuit, a magnetic circuitbreaker having a switch in said load circuit and an actuating coil, an overload relay having a'switch and electromagnetic means and means associating said electromagnetic means withsaid relay switch to open the latter upon predetermined energization of the former, connecting means arranged for actuation by closing movement of said breaker switch to close said relay switch, operatorcontrolled means for selectively energizing said breaker coil to close said relay switch or for inserting said electromagnetic means in said load circuit, and operator-controlled means for energizing said breaker coil dependent upon closing of said relay switch, whereby said apparatus may be operated subject to being disconnected by the opening of said breaker in response to said relay. 4. Control means for electric apparatus comprising a load circuit, a magnetic circuitbreaker having a switch in said loadcircuit and an actuating coil, an overload relay having a switch and electromagnetic means arranged in said load circuit and toggle means associating said electromagnetic means with a said relayswitch to open the latter upon predetermined energization of the former, additional toggle means associated with said first named toggle means and arranged for actuation by closing movement of said breaker switch to close said relay switch, operatorcontrolled means for energization of said breaker coil to close said relay switch, and operator-controlledmeans for energizin said breaker coil dependent upon closing 0 said relay switch, whereby said apparatus may be operated subject to being disconnected by the opening of said breaker in response to said 1 relay.

5. Control means for electric apparatus comprising a load circuit, a magnetic circuitbreaker having a switch in said load circuit and an actuating coil, an overload relay having a switch and electromagnetic means arranged in said load circuit and having a double tog le adapted when straightened, to close said re ay switch, said electromagnetic means being arranged to control one oint of said toggle to break the same to open said relay switch, said breaker switch being arran ed to straighten by closing movement, the ot er joint of said toggle to close said relay switch, operator-controlled means for energization of said breaker coil to close said relay switch,

' and operator-controlled means for energizing said breaker coil dependent upon closing of said relay switch, whereby said apparatus may be operated subject to being disconnected by the opening of said breaker in response to said re ay.

In testimony whereof we hereby aflix our signatures.

, EDWIN R. GOLDFIELD. CAPERTON HORSLEY. 

